The present invention pertains to a method for testing subscriber's equipment which can detect the malfunctions of the subscriber's equipment. The conventional method for testing subscriber's equipment found the troubles on the subscriber's side just by status measurement of the subscriber's line, and needed additional testing boards or reception boards because it could not support to call the subscriber and to test the subscriber's phone. And only ring test was possible for line maintenance personnel.
In addition, there were some other reasonable methods for the testing of the subscriber's equipment as follows. One was to use a connection method for testing the subscriber's equipment on a semi-electronic exchanger by connecting the test equipments on the electronic exchanger through the semi-electronic exchanger. And another was to install some additional testing methods and equipments for the maintenance of the subscriber's equipment in every exchanger, even though this method needed more cost for the subscriber's parts inside the exchanger. Currently, the test following the subscriber's request and the automatic test were taking the main stream. And these methods could influence the service for the subscriber since they interrupted the service from the beginning of the test to the end of the test. On ring test by line maintenance personnel, after the personnel dials the specified number(118) to the subscriber's phone, if a subscriber does hook-on, then, he sends a ring to the subscriber. After that, if the subscriber does hook-off, he stops sending a ring. Then, the subscriber is recovered to the service state. The problem of the said method was to stop the subscriber's service for the maintenance test as shown in the above.